The rapid advancement of hypersonic vehicles has created an urgent demand for lightweight, multifunctional thermal protection systems (TPS) capable of withstanding extreme temperatures while simultaneously absorbing electromagnetic wave (EMW) radiation. Silicon carbide (SiC) aerogels have long been recognized as promising candidates due to their high melting point, exceptional oxidation resistance, and tunable dielectric properties. However, conventional single-scale SiC architectures, whether coarse fiber networks or sparse nanowire scaffolds, inevitably face a fundamental performance bottleneck: coarse fibers lack sufficient polarization interfaces for effective EMW attenuation, while fine nanowires lack macroscopic structural durability and thermal stability. This “fish‑and‑bear‑paw” dilemma has long hindered the integration of efficient wave absorption and reliable thermal insulation in a single material system. Fabrication challenges further compound the problem, as traditional sol-gel routes require energy-intensive supercritical drying and high-temperature sintering that are difficult to scale for large-area or arbitrarily shaped components.
Recently, a team of material scientists led by Professor Rujie He from Beijing Institute of Technology, China, reported a novel multiscale all-ceramic composite framework for multifunctional thermal protection and EMW absorption. This material consists of an ultralight SiC f scaffold assembled via room-temperature ceramic papermaking and inter-fiber grown SiC nw , subjected to CVI processing. By modulating the matrix fiber length to 5 mm (SFW‑5M), the team successfully created open macropores of hundreds of micrometers that eliminate gas transport barriers, allowing uniform growth of ultra‑high‑aspect‑ratio SiC nanowires within the inter‑fiber voids. The resulting SFW‑5M aerogel exhibits an ultralow density of merely 0.23 g·cm -3 and an exceptionally low room‑temperature thermal conductivity of 64 mW·m -1 ·K -1 . This work highlights the advantages of multiscale structural design and confirms the superior wave attenuation and fire-strengthening mechanism of the hierarchically cross-linked fiber/nanowire interfaces.
The team published their work in Journal of Advanced Ceramics on August 21, 2026.
“Inspired by traditional Chinese papermaking technology, our room-temperature ceramic papermaking route allows SiC fibers to undergo gravity-driven self-assembly under ambient conditions without requiring size-limiting equipment, pressure, or high-temperature sintering. This yields a highly flexible precursor platform capable of producing large-format components with complex geometries,” said Rujie He, professor at Institute of Advanced Structure Technology, Beijing Institute of Technology (China).
By modulating the matrix fiber length to 5 mm (SFW-5M), the team successfully unlocked sufficient open macroporous clearance across hundreds of micrometers. “This open scaffold eliminates gas transport barriers, allowing ferrocene-catalyzed VLS growth to uniformly grow ultra-high-aspect-ratio SiC nanowires within the inter-fiber voids.” said Rujie He. The resulting SFW-5M aerogel exhibits an ultralow density of merely 0.23 g·cm -3 and an exceptionally low room-temperature thermal conductivity of 64 mW·m -1 ·K -1 .
In thermal protection testing, the multiscale aerogel demonstrated outstanding thermal shielding. When subjected to direct exposure under a 1000 °C butane flame, the back-surface temperature of the 8 mm thick SFW-5M specimen was reliably restricted to approximately 250 °C—a 75% reduction relative to the heat source. “While coarse fibers block thermal radiation at high temperatures, the fine nanowire network suppresses gas-phase heat convection, conferring superior thermal insulation.” explained Rujie He. Post‑ablation structural integrity was maintained without spallation, confirming excellent high‑temperature stability.
“The multiscale architecture achieves seamless cooperation across scales. At the macroscale, the millimeter fibers form primary channels for continuous wave scattering. At the micro- and nanoscales, the dense nanowires create interconnected 3D conductive pathways and abundant heterogeneous interfaces, driving intense interfacial and dipolar polarization.” explained Rujie He.
After introducing nanowires, SFW‑5M achieved an impressive minimum reflection loss (RL min ) of -46.62 dB. Crucially, rather than undergoing catastrophic mechanical collapse or functional degradation during high-temperature service, exposure to 1000 °C air ablation for 1 hour triggered a striking “fire-strengthening” phenomenon. Post-ablation compressive peak stress increased significantly, while the Effective Absorption Bandwidth (EAB) expanded from 4.6 GHz to an extraordinary 11.5 GHz—spanning 72% of the 2-18 GHz range and fully covering the C, X, and Ku radar bands. “During high-temperature ablation, thermal oxidation forms a thin, amorphous SiO 2 layer that fuses contact points between fibers and nanowires into neck-like cross-linked joints, reinforcing compressive strength. Simultaneously, the core-shell SiC@SiO 2 heterostructures optimize surface impedance matching and enhance interfacial charge relaxation under alternating fields,” noted the Rujie He. This “fire‑strengthening” effect overturns the conventional wisdom that “high temperature equals degradation.”
Moreover, the scalable room‑temperature ceramic papermaking route enables fabrication of large‑format (400 mm × 300 mm) and complex‑shaped components without size‑limiting equipment, providing a practical path toward industrialization.
Through the combination of room-temperature ceramic papermaking and CVI, this study successfully fabricated multiscale SiC f /SiC nw all-ceramic aerogels that overcome the performance limitations of single-scale materials, achieving a unified integration of ultralow density, efficient thermal insulation, broadband electromagnetic wave absorption, and a “fire‑strengthening” effect. This multiscale design paradigm, encompassing “room‑temperature forming, high‑temperature growth, and ablation‑induced strengthening”, offers a viable technological pathway for multifunctional thermal protection systems intended for extreme aerospace environments.
Other contributors include Jingyi Chen, Wanxun Li, Chang Liu, Wenqing Wang, Ying Li from the Institute of Advanced Structure Technology and Marine Science and Technology Domain at Beijing Institute of Technology, China.
About Author
Rujie He is a professor at Beijing Institute of Technology. His research centers on advanced manufacturing and multifunctional structural design of ceramics and composites, combining additive manufacturing (vat photopolymerization, direct ink writing, binder jetting) with wet forming (ceramic papermaking, needled felt forming). His work addresses forming mechanisms, defect control, lightweight/toughened structures, multi-scale mechanics, and structure–function integration. He has led 4 NSFC projects and over 20 defense/engineering projects. He has published over 160 SCI papers as first/corresponding author with more than 9,000 citations, including over 10 ESI Highly Cited Papers and 2 Hot Papers, and holds more than 10 patents. He serves as Deputy Director of the Beijing Key Laboratory of Lightweight Multifunctional Composite Materials and Structures; Vice Chair of the Ceramic Matrix Composites Branch and member of the Thermal Protection Composites Branch of the Chinese Society for Composite Materials; and member of the Oral and Craniomaxillofacial Materials Branch of the Chinese Society for Biomaterials. He is also Associate Editor for Journal of Advanced Ceramics , npj Advanced Manufacturing , and International Journal of Applied Ceramic Technology , and serves on the editorial/youth editorial boards of over 10 international/domestic journals.
Funding
This work was financially supported by the National Natural Science Foundation of China (No. 52572094), and the China Postdoctoral Science Foundation (2025M784240).
DOI LINK: 10.26599/JAC.2026.9221360
About Journal of Advanced Ceramics
Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen . JAC’s 2025 IF is 14, ranking in Top 1 (1/34, Q1) among all journals in “Materials Science, Ceramics” category, and its 2025 CiteScore is 24.6 (6/133) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508
Journal of Advanced Ceramics
Multiscale SiC fiber/nanowire aerogels for broadband electromagnetic wave absorption via scalable ceramic papermaking coupled with CVI
21-Aug-2026